Feb. 8, 2010 -- Nearly one in three overweight adolescents don't think they
have a weight problem.

A new study shows that nearly a third of adolescents who would be classified
in medical terms as overweight do not think they are overweight. Researchers
also found significantly more boys than girls had misperceptions about their
weight.

"We found that the proportion of overweight adolescents who were
misperceivers (reported that they were 'about right' or 'underweight') was
substantial, ranging from 29% to 33% from 1999 through 2007," writes researcher
Nicholas Murphy Edwards, MD, of the University of Minnesota in Minneapolis, in
Pediatrics.

Previous studies have shown that the prevalence of overweight children and
adolescents has doubled in the last 30 years, with more than 30% of children
now classified as obese or overweight. Children are considered overweight if
their body mass index (BMI, an index of weight in relation to height) is at or
above the 85th percentile and obese if their BMI is at or above the 95th
percent.

Weight Perception Is Important

Researchers say how children and adolescents perceive their weight is
important because boys and girls who acknowledge that they are overweight are
much more likely to take steps to try to maintain or lose weight.

The study was based on data collected by the national Youth Risk Behavior
Surveillance System, which surveyed a large nationwide sample of ninth through
12th grade students every other year from 1999 to 2007.

The results showed the percentage of overweight teenagers who did not
believe they were overweight ranged from 29% to 33% during the study
period.

For example, in 2007 researchers found that 0.8% of overweight participants
described themselves as "very underweight," 1.7% as "slightly underweight," 30%
as "about the right weight," 56% as "slightly overweight," and 12% as "very
overweight."

In 2007, 40% percent of boys had misperceptions about their weight compared
to 23% of girls. Hispanic and African-American respondents were also more
likely to misperceive their weight status.